2.54mm Machined Round Pin Female Header Socket 40 Pin Gold Over Nickel Precision Turned

Stamped contacts are fast and inexpensive, but they cannot match the spring memory of a machined cage. This 2.54mm round pin female header is built from precision turned brass sleeves, each one carrying a six finger contact cage that wraps a round or square post on all sides. The result is a socket whose insertion force stays flat over hundreds of cycles, which is why machined sockets dominate burn-in boards, IC test sockets and any assembly that is mated and unmated during service rather than once at the factory.

The insulator is PPS rather than nylon. PPS holds its dimensions under continuous 125 C operation and does not creep when the socket is clamped into a test fixture, so the 2.54mm contact spacing stays true after years of thermal cycling. Gold plating of 0.76 micron sits over a 2.5 micron nickel barrier, keeping contact resistance near 10 milliohms and blocking the nickel diffusion that eventually dulls thin flash coatings on cheaper parts.

• Precision turned contacts: Each brass sleeve is machined on a Swiss lathe, giving a concentric bore that keeps insertion force consistent from pin one to pin forty.
• Six finger contact cage: The internal cage grips round and square posts alike and maintains spring memory far beyond the life of a stamped contact.
• Gold 0.76 micron over nickel: A 2.5 micron nickel barrier blocks diffusion, so contact resistance stays near 10 milliohms through the full service life.
• PPS insulator: Polyphenylene sulphide resists 260 C soldering, solvents and continuous 125 C operation without dimensional creep.
• Low and stable insertion force: Mating force remains predictable after 500 cycles, which protects plated through holes on reworked boards.
• Socketable IC footprint: The 2.54mm single row format accepts standard DIP outlines, turned pin adapters and wire wrap posts.

Machined sockets are specified wherever the connection has to survive repeated insertion. Burn-in and life test boards use them because a stamped contact loses spring force after a few hundred oven cycles. Automotive ECU programmers and calibration rigs rely on them to protect the plated through holes of expensive control units. Audio and instrument designers choose them for op amp and DIP adapter sockets, where a tight, low resistance contact keeps noise floors low. They are also the standard choice for wire wrap prototyping, crystal and relay sockets, and any legacy board that is repaired rather than replaced.

We machine sleeves in brass or beryllium copper, and can raise the gold thickness to 1.27 or 1.5 micron for high insertion count fixtures. Single row lengths from 2 to 40 positions are stocked as strip material, so short runs need no new tooling. Optional features include a closed bottom for through hole protection, a solder tail length matched to 1.6mm or 2.4mm boards, and an insulator in PPS or high temperature PEI. Custom contact cages for 0.5mm round posts and for square 0.64mm posts are both available, and engineering samples ship within five working days of drawing approval.

Machined sockets leave the line in anti-static tubes of 20 or 50 pieces, which protects the turned contacts from lateral impact during transport. Tubes are boxed into export cartons with foam end caps, and each carton carries a lot number that links back to the plating certificate for that barrel. Because the gold layer is the cost driver on this product, every shipment includes a plating thickness report measured by X-ray fluorescence at three points on the batch. Cartons are sealed with tamper evident tape and marked with humidity indicators for sea freight. Distributors can request neutral tubes, own-brand labels and barcoded cartons, and we hold a three year archive of dimensional reports for every lot shipped.